Satellite To Fall To Earth in Uncontrolled Descent

The European Space Agency estimates that a satellite weighing 2,425 pounds (1,100 kilograms) will begin its orbital decay sometime this week and then hurl back to Earth in an uncontrolled descent from an orbital height of about 139 miles (224 kilometers).

On October 18, the ESA reported that the pressure in the satellite’s fuel system had dropped below 2.5 bar, which is the pressure needed to fire the ion engine. It was estimated then that there was about 350g of xenon left in the fuel tank. If the engine continues to function until the tank is empty, orbital decay would start around October 26, 2013. However, ESA controllers expect the ion engine to terminate well before that.

The ESA cautioned that, while most of the satellite will disintegrate in the atmosphere, several parts might reach Earth’s surface. Exactly when and where the space junk debris will crash cannot yet be predicted, but the affected area will be narrowed down by ESA scientists closer to the time of re-entry. Re-entry is expected to happen about three weeks after the fuel is depleted.